What is a major advantage of an end-fed half-wave antenna (EFHW)?

An End-Fed Half-Wave (EFHW) antenna is highly valued because its resonant length on a fundamental frequency also presents a high impedance on its harmonically related frequencies. With a suitable impedance matching transformer, a single wire can operate efficiently on multiple bands without needing complex mechanical traps. Other options represent disadvantages or false claims. For instance, an EFHW absolutely requires a matching network (like a 49:1 or 64:1 unun) to be fed with standard 50-ohm coaxial cable, because the feedpoint impedance at the end of a half-wave wire is extremely high, often in the thousands of ohms. Additionally, because EFHW antennas are fed at the end and often use the coax shield as a counterpoise, they are actually highly prone to developing common-mode currents, meaning a good choke is usually required.